Device for cushioning the shock of ships



Apnfifi 28, T1936. (3. E. F. DUBOIS DEVICE FOR CUSHIONING THE SHOCK OFSHIPS Filed Feb. 2, 1935 INVENTOR M w (2 ATTORNEYS CHARLES EMILEFERDINAND DUBOLS BY f Patented Apr. 28, 1936 DEVICE FOR CUSHIONING THESHOCK OF SHIPS Charles Emile Ferdinand Dubois, Maisons-Laffitte, France,assignor to Socit S. I. M. E. C. (Societe Industrielle de MaterielDEntreprise et de Construction), Paris, France Application February 2,1933, Serial No. 654,841 In France February 15, 1932 7 Claims.

The present invention has for its object a device adapted to cushion theshocks which may be given by ships against the constructive works whichthey approach, such as quays, moles, piers, stockades, wharfs, etc.

Damages so much the more serious as the shock is more violent may becaused either to the ship, or to the constructive work, or to both, but,in the majority of cases, constructive works are capable of receivingwithout great damage extremely important shocks, and it is nearly alwaysthe ship which runs the greatest risk of damages so much the moreserious as its tonnage is greater.

The menace of these damages justifies the utilization, upon accosting,of powerful active means such as tugs, towing windlasses on mooringbuoys, etc., for slowly stopping the ship in the right place alongsidethe work; this menace also justifies the interposition between the shipand work of passive, movable or fixed fenders more or less distortableand having some resiliency, such as fascines, bollards, etc., thesepassive fender subsisting after the ship has come alongside: theyprevent the ship from heavily striking against the work, either underthe action of the waves which cause it to roll, or under the action ofthe wind or of eventual currents which can drive it against the work.

The fenders used up to this day can be distorted only to a slight extentand are scarcely efiicient when ships having tonnages of 50,000 tons andmore, such as are actually built, are considered.

The violence of the shock, that is to say the magnitude of the reactionof the work onthe ship is proportional to the mass of the latter as wellas to the square of the number expressing the speed at which the shipmoves towards the work when approaching; but the violence of the shockor of the reaction of the constructive work diminishes in proportion asthe possibility of displacement of the point of contact (that is to sayof distortion of the body receiving the shock) increases.

This conception of the necessity of a great distortion is in particularthe reason for which large rafts of tree trunks are used as fenders inNew York Harbor in order that large ocean liners may enter without greatdanger between two adjacent piers and come alongside the same, whichmanoeuvre must be effected notwithstanding the relatively violentcurrent of the Hudson River which pushes the ships against the wing-wallof the pier; these large rafts, which are several meters wide, arecompletely crushed during the manoeuvre, and, after crushing, they havelost about of their width and they can be used only for one accostingoperation.

According to the present invention, the member receiving the shock cannot only be sub- 5 jected to great distortion, but it can alsoautomatically resume its initial condition after the ship has stopped;such a shock absorber constituted a real advance by reducing theviolence of the shock to a value computed as admisible for 10 the ship,as well as for the constructive work if the latter is not veryresistant.

The proposed shock absorber will preferably be constituted by a fixedfender permanently arranged on the constructive work and capable of 15being subjected to great resilient distortion. A form of construction ofthis device is illustrated, by way of example, in the accompanyingdrawmg.

Fig. 1 is a vertical section of the shock ab- 20 sorber at the beginningof the shock at the moment the ship comes in contact with it.

Fig. 2 is a vertical section of the shock absorber at the end of theshock after the ship has stopped.

Fig. 3 is a horizontal section of the shock absorber at the beginning ofthe shock.

Fig. 4 is a vertical section, on an enlarged scale, showing the detailsof the device.

The proposed shock absorber is constituted as 30 follows:

A pendular body I is freely hung from a fixed shaft, rigid with theconstructive work. In the wall of this constructive work, in contactwith the water, is provided a recess, the side walls 3 35 of whichsupport the shaft 2 and between which can oscillate the pendular body I,said side walls acting as guides for said pendular body.

In the rear wall 3a of the recess opens a hydraulic cylinder 6 firmlyanchored in the fixed 40 constructive work and which terminates at therear in a tank 8 arranged in a well 13 opening in the platform of thefixed constructive work and closed by a cover M.

In the cylinder 6 is slidably mounted a piston 45 5; on which is pivoteda connecting rod 4 pivoted, on the other hand, on a shaft I6, rigid withthe pendular body 1. Between the piston 5 and; the bottom of thecylinder 6 is interposed a compression spring 9 adapted to facilitatethe return of 50 the pendular body to its initial position.

The bottom of the cylinder 6 is connected to the interior of the tank 8by a delivery channel I! in which is arranged a ball delivery valve 1,adapted to open inwardly of" the tank 8 in opposition to the action of acompression spring H. In the bottom of the cylinder 6 is moreoverprovided a suction channel IS, in which is arranged a ball valve In,adapted to open inwardly of the cylinder 5 in opposition to the actionor a compression spring l9.

In the top of the tank 8 is provided an opening 12 which puts it incommunication with the interior of the well l3.

The cylinder 6 is filled with a liquid 20 which is delivered into thetank 8 through the valve 1, when the piston moves backwards andcompresses the spring 9, and which is sucked through the valve II], whenthe piston moves forward. The air contained in the tank 8 above theliquid can easily escape through the opening l2, during the deliveryperiod, and can return during the suction period.

The operation of the device is as follows:

When a ship strikes upon the pendular body I, the latter is pushed backtowards the rear wall 3a of the recess 3, by rocking about its shaft 2.Through the medium of the connecting rod 4, the piston 5 is pushed backwithin the cylinder 6; it compresses the spring 9 and delivers theliquid 20 into the tank 9 through the delivery valve 1. This backwardmovement is checked to a great extent by the weight of the pendular bodyI, the compression of the spring 9 and the checking of the liquid in thedelivery channel ll. At the end of the backward movement, the entiredevice slowly returns towards the position of rest under the action ofthe weight of the pendular body and of the spring 9. This movement isalso greatly checked by the fact that the liquid, previously deliveredinto the tank 8, is sucked through the narrow channel 18.

What I claim as my invention and desire to secure by Letters Patent is:

1. In a shock absorber adapted to deaden the shock of a ship against afixed structure, the combination of a pair of side walls rigid with saidstructure and spaced apart to form an open recess in said structure, anaxle transversely disposed in said recess and secured to the side wallsat a level above the highest water level, a buffer member pendentlymounted and supported upon said axle in said recess so as to expose aportion of said buffer member to be engaged by the approaching ship, anda fluid press comprising a cylinder secured to said fixed structure andcontaining a fluid, a piston within said cylinder, a tank, an outletchannel and a return channel connecting said cylinder to said tank, aspring delivery valve mounted on said outlet channel, means acting onsaid delivery valve for checking the fluid delivered, and a suctionvalve mounted on said return channel, said bufier member beingoperatively connected to said piston in order to force the fluidcontained in the cylinder towards the tank through the delivery valvewhen said buffer member is moved in the direction of the fixedstructure.

2. In a device for deadening the shock of the impact of a ship against afixed structure, the combination of a pair of side walls rigid with saidstructure and spaced apart to form an open recess in said structure, ahorizontal axle held in said recess by both of said side walls inparallelism with the general direction of said fixed structure, and abuffer member pendently mounted and supported upon said axle in saidrecess and exposed to make contact with said ship, there being a rearwall in said recess which is sufiiciently distant from the buffer memberto allow the latter to oscillate, and the vertical profile of theshock-receiving surface of said bufier member having a convex curvatureon a large portion of its height, and means interposed between the fixedstructure and the buifer member to check the oscillations of the latter.

3. In a device for deadening the shock of the impact of a ship against afixed structure, the combination of a pair of side Walls rigid with saidstructure and spaced apart to form an open recess in said structure,there being a rear wall in said recess, a horizontally disposed pivotmeans supported by at least one of said side walls in spaced positionfrom said rear wall and above the water level, a bufier member pendentlymounted and supported in said recess upon said pivot means and exposedto make contact with said ship, which bufier member ,comprises apendular body having a plane of oscillation disposed at right angles tosaid fixed structure, the rear wall of said recess being suflicientlydistant from said buffer member to allow the latter to oscillate in thedirection of the fixed structure, and means interposed between the fixedstructure and the bufier member to check the oscillations of the latter.

4. In a device for deadening the shock of the impact of a ship against afixed structure, the combination of a pair of side walls rigid with saidstructure and spaced apart to form an open recess in said structure,there being a rear wall in said recess, a horizontally disposed pivotmeans supported by at least one of said side walls in spaced positionfrom said rear wall and above the water level, a buffer member pendentlymounted and supported in said recess upon said pivot means and exposedto make contact with said ship, which bufier member comprises a pendularbody, the rear walls of the recess and of the buffer member also leavinga space between them when the latter is in its position of rest and theside walls of the recess holding and guiding the buffer member, andmeans interposed between the fixed structure and the buffer member tocheck the oscillations of the latter.

5. In a device for deadening the shock of the impact of a ship against afixed structure, the combination of a pair of side walls rigid with saidstructure and spaced apart to form an open recess in said structure, ahorizontal axle held in said recess by both of said side walls at alevel above the highest water level, and a buffer member suspended uponsaid axle and exposed to make contact with the ship, said buffer memberbeing held in position of rest under the action of its own weight, acylinder in said fixed structure disposed at right angles to said axle,a piston movable in said cylinder, means for connecting said piston tosaid suspended buffer member, a spring delivery valve located in adelivery channel provided in the bottom of said cylinder, a suctionvalve located in a suction channel also provided in the bottom of saidcylinder, and a tank containing a liquid into which both said deliveryand suction channels open.

6. In a device for deadening the shock of the impact of a ship against afixed structure, the combination of a pair of side walls rigid with saidstructure and spaced apart to form an open recess in said structure, ahorizontal axle held in said recess by both of said side walls at alevel above the highest water level, and a buffer member pendentlymounted upon said axle and exposed to make contact with the ship, saidbufier member being held in position of rest under the action of its ownweight and having a shock-receiving surface which is curved in thedirection of its height, a cylinder in said fixed structure disposed atright angles to said axle, a piston movable in said cylinder, means forconnecting said piston to said buffer member, a compression springinterposed between the bottom of said cylinder and said piston, adelivery valve located in a delivery channel provided in the bottom ofsaid cylinder, a suction valve located in a suction channel alsoprovided in the bottom of said cylinder, and a tank containing a liquidand into which both said delivery channel and said suction channel open.

7. In a device for deadening the shock of the impact of a ship against afixed structure, the combination of a pair of side walls rigid with saidfixed structure and spaced apart to form an open recess in saidstructure, a horizontal axle held in said recess by both of said sidewalls at a level above the highest water level, and a buffer memberpendently mounted upon said axle in exposed position in said recess soas to be capable of making contact with the ship, said buiTer holdingthe position of rest under the action of its own weight, a hydraulicpress comprising a cylinder rigid with said fixed structure andcontaining a delivery valve and a suction valve, a piston movable insaid cylinder, and means connecting the piston to said buifer.

CHARLES EMILE FERDINAND DUBOIS.

